Warning W00040011 & the elusive "Volume 1"

I've been fatihfully backing up my data for upwards of two years, but now that I need to restore some lost files, I find that none of the backed up data is of any use to me. Even though I can 'see it' on the remote HD, I can't restore any of it. Trying to restore just either locks things up, asks for that elusive 'Volume 1' or clunks around a bit then tells me every file I try is corrupted.

I have searched this forum and found multiple queries re this problem and have almost come to the conclusion that there might not be a solution...at least Acronis doesn't seem to be able to come up with one for most of the people having this difficulty.

I need a simple 'dummies' explanation please, as I'm getting totally frustrated with this.